What are different MSC protocols ?

MAP (Mobile Application Part)

Used to control queries to the different databases in the mobile radio network (HLR, VLR and EIR).

MAP responsibilities include access and location management (e.g. where is the called subscriber currently?), MSC-MSC

handover, security functions, O&M, SMS and supplementary services.

TCAP (Transaction Capabilities Application Part)

Provides universal calls and functions for handling requests to distributed application processes.

ISUP (ISDN User Part)

Controls interworking (e.g. call setup/takedown) between PLMNs and other networks, and provides the same basic

functionalities as TUP.

INAP (Intelligent Network Application Part)

Implements intelligent supplementary services (e.g. free call, time-dependent routing functions in a central service center).

TUP (Telephone User Part)

Implements interworking between PLMNs and other networks. TUP is normally used to provide international connections and is slowly being replaced by ISUP.